2. the lower limb perfusion by using MRI blood oxygenation-level dependent (BOLD) and dynamic contrast enhancement sequences and measures the extracellular volume fraction (ECV) as an indicator of fibrosis severity in calf muscles, from one to 52 weeks post-revascularization in patients with peripheral artery disease who have undergone endovascular revascularization -/+ bypass surgery for moderate to severe claudication or ischemic rest pain.